Paulus123 wrote: I quess to my ear using the subjunctive sounds a little to tenative for a definition. How would you classify this use of the subjunctive? Is this a style commonly used for definitions in Latin?
Allen & Greenough, §482 wrote:The tenses of the Subjunctive in Dependent Clauses follow special rules for the Sequence of Tenses.
Allen & Greenough, §485.b wrote:After a primary tense the Perfect Subjunctive is regularly used to denote any past action.
You have indeed a dependent clause referring to a condition that might
pertain (so subjunctive in Latin). Were the condition to pertain (or have pertained,—so past tense), then as a consequence, "it is a rectilinear angle". Convoluted, I know, but I'm trying to justify the writer's thinking. In English, you tend to say "it will
be a rectilinear angle", which is no less strange, I suggest, in referring to the potentiality of a general truth. Dependentem clausulam quidem habes, ut conditionem quae pertineat demonstrat (ideò subjunctivo modo latiné). Si conditio pertinuisset, tunc ab eam causam, est angulus rectilineus. Tortuosum, scio, sed mentem scriptoris excusare conor. Anglicè paenè dicas "it will be a rectilinear angle" , quod non minùs externum est, suggero, veri potentiam generalis in demonstrando.
I'm writing in Latin hoping for correction, and not because I'm confident in how I express myself. Latinè scribo ut ab omnibus corrigar, non quod confidenter me exprimam.